In our study, SDC1 was elevated in ‘good’ adult Fontan patients compared to matched controls—it would be highly interesting to understand patients’ extent of collateral vessels in the Fontan circuit and their general hepatic status: patients with collateral vessels may have lower central venous pressures and may (to a certain degree) have preserved Fontan hemodynamics; this may prevent the development of or limit the extent of liver disease. Here, SDC1 is linked to liver disorder.